/**
* @file util/server_nc.c
* @brief convenience functions for transmission of
- * a notification stream
+ * a notification stream
* @author Christian Grothoff
*/
#include "platform.h"
#include "gnunet_common.h"
#include "gnunet_connection_lib.h"
+#include "gnunet_container_lib.h"
#include "gnunet_scheduler_lib.h"
#include "gnunet_server_lib.h"
#include "gnunet_time_lib.h"
+#define LOG(kind,...) GNUNET_log_from (kind, "util", __VA_ARGS__)
+
+/**
+ * Entry in list of messages pending to be transmitted.
+ */
struct PendingMessageList
{
+ /**
+ * This is a doubly-linked list.
+ */
struct PendingMessageList *next;
+ /**
+ * This is a doubly-linked list.
+ */
+ struct PendingMessageList *prev;
+
+ /**
+ * Message to transmit (allocated at the end of this
+ * struct, do not free)
+ */
const struct GNUNET_MessageHeader *msg;
+ /**
+ * Can this message be dropped?
+ */
int can_drop;
};
+/**
+ * Lists of clients we manage for notifications.
+ */
struct ClientList
{
+ /**
+ * This is a doubly linked list.
+ */
struct ClientList *next;
+ /**
+ * This is a doubly linked list.
+ */
+ struct ClientList *prev;
+
+ /**
+ * Overall context this client belongs to.
+ */
struct GNUNET_SERVER_NotificationContext *nc;
+ /**
+ * Handle to the client.
+ */
struct GNUNET_SERVER_Client *client;
- struct GNUNET_CONNECTION_TransmitHandle *th;
+ /**
+ * Handle for pending transmission request to the client (or NULL).
+ */
+ struct GNUNET_SERVER_TransmitHandle *th;
+ /**
+ * Head of linked list of requests queued for transmission.
+ */
struct PendingMessageList *pending_head;
+ /**
+ * Tail of linked list of requests queued for transmission.
+ */
struct PendingMessageList *pending_tail;
+ /**
+ * Number of messages currently in the list.
+ */
unsigned int num_pending;
};
/**
- * The notification context is the key datastructure for a conveniance
+ * The notification context is the key datastructure for a convenience
* API used for transmission of notifications to the client until the
* client disconnects (or the notification context is destroyed, in
* which case we disconnect these clients). Essentially, all
struct GNUNET_SERVER_NotificationContext
{
+ /**
+ * Server we do notifications for.
+ */
struct GNUNET_SERVER_Handle *server;
- struct ClientList *clients;
+ /**
+ * Head of list of clients receiving notifications.
+ */
+ struct ClientList *clients_head;
+ /**
+ * Tail of list of clients receiving notifications.
+ */
+ struct ClientList *clients_tail;
+
+ /**
+ * Maximum number of optional messages to queue per client.
+ */
unsigned int queue_length;
};
+/**
+ * Client has disconnected, clean up.
+ *
+ * @param cls our 'struct GNUNET_SERVER_NotificationContext *'
+ * @param client handle of client that disconnected
+ */
static void
-handle_client_disconnect (void *cls,
- struct GNUNET_SERVER_Client *client)
+handle_client_disconnect (void *cls, struct GNUNET_SERVER_Client *client)
{
struct GNUNET_SERVER_NotificationContext *nc = cls;
struct ClientList *pos;
- struct ClientList *prev;
struct PendingMessageList *pml;
- prev = NULL;
- pos = nc->clients;
- while (NULL != pos)
- {
- if (pos->client == client)
- break;
- prev = pos;
- pos = pos->next;
- }
- if (pos == NULL)
+ if (NULL == client)
+ {
+ nc->server = NULL;
return;
- if (prev == NULL)
- nc->clients = pos->next;
- else
- prev->next = pos->next;
+ }
+ for (pos = nc->clients_head; NULL != pos; pos = pos->next)
+ if (pos->client == client)
+ break;
+ if (NULL == pos)
+ return;
+ LOG (GNUNET_ERROR_TYPE_DEBUG,
+ "Client disconnected, cleaning up %u messages in NC queue\n",
+ pos->num_pending);
+ GNUNET_CONTAINER_DLL_remove (nc->clients_head,
+ nc->clients_tail,
+ pos);
while (NULL != (pml = pos->pending_head))
- {
- pos->pending_head = pml->next;
- GNUNET_free (pml);
- }
+ {
+ GNUNET_CONTAINER_DLL_remove (pos->pending_head, pos->pending_tail, pml);
+ GNUNET_free (pml);
+ pos->num_pending--;
+ }
+ if (NULL != pos->th)
+ {
+ GNUNET_SERVER_notify_transmit_ready_cancel (pos->th);
+ pos->th = NULL;
+ }
+ GNUNET_SERVER_client_drop (client);
+ GNUNET_assert (0 == pos->num_pending);
GNUNET_free (pos);
}
* @param server server for which this function creates the context
* @param queue_length maximum number of messages to keep in
* the notification queue; optional messages are dropped
- * it the queue gets longer than this number of messages
+ * if the queue gets longer than this number of messages
* @return handle to the notification context
*/
struct GNUNET_SERVER_NotificationContext *
GNUNET_SERVER_notification_context_create (struct GNUNET_SERVER_Handle *server,
- unsigned int queue_length)
+ unsigned int queue_length)
{
struct GNUNET_SERVER_NotificationContext *ret;
ret = GNUNET_malloc (sizeof (struct GNUNET_SERVER_NotificationContext));
ret->server = server;
ret->queue_length = queue_length;
- GNUNET_SERVER_disconnect_notify (server,
- &handle_client_disconnect,
- ret);
+ GNUNET_SERVER_disconnect_notify (server, &handle_client_disconnect, ret);
return ret;
}
* @param nc context to destroy.
*/
void
-GNUNET_SERVER_notification_context_destroy (struct GNUNET_SERVER_NotificationContext *nc)
+GNUNET_SERVER_notification_context_destroy (struct
+ GNUNET_SERVER_NotificationContext
+ *nc)
{
struct ClientList *pos;
struct PendingMessageList *pml;
- while (NULL != (pos = nc->clients))
+ while (NULL != (pos = nc->clients_head))
+ {
+ GNUNET_CONTAINER_DLL_remove (nc->clients_head,
+ nc->clients_tail,
+ pos);
+ if (NULL != pos->th)
{
- nc->clients = pos->next;
- GNUNET_SERVER_receive_done (pos->client, GNUNET_NO);
- GNUNET_SERVER_client_drop (pos->client);
- while (NULL != (pml = pos->pending_head))
- {
- pos->pending_head = pml->next;
- GNUNET_free (pml);
- }
- GNUNET_free (pos);
+ GNUNET_SERVER_notify_transmit_ready_cancel(pos->th);
+ pos->th = NULL;
}
- GNUNET_SERVER_disconnect_notify_cancel (nc->server,
- &handle_client_disconnect,
- nc);
+ GNUNET_SERVER_client_drop (pos->client);
+ while (NULL != (pml = pos->pending_head))
+ {
+ GNUNET_CONTAINER_DLL_remove (pos->pending_head, pos->pending_tail, pml);
+ GNUNET_free (pml);
+ pos->num_pending--;
+ }
+ GNUNET_assert (0 == pos->num_pending);
+ GNUNET_free (pos);
+ }
+ if (NULL != nc->server)
+ GNUNET_SERVER_disconnect_notify_cancel (nc->server,
+ &handle_client_disconnect, nc);
GNUNET_free (nc);
}
* @param client client to add
*/
void
-GNUNET_SERVER_notification_context_add (struct GNUNET_SERVER_NotificationContext *nc,
- struct GNUNET_SERVER_Client *client)
+GNUNET_SERVER_notification_context_add (struct GNUNET_SERVER_NotificationContext
+ *nc,
+ struct GNUNET_SERVER_Client *client)
{
struct ClientList *cl;
+ for (cl = nc->clients_head; NULL != cl; cl = cl->next)
+ if (cl->client == client)
+ return; /* already present */
cl = GNUNET_malloc (sizeof (struct ClientList));
- cl->next = nc->clients;
+ GNUNET_CONTAINER_DLL_insert (nc->clients_head,
+ nc->clients_tail,
+ cl);
cl->nc = nc;
cl->client = client;
- nc->clients = cl;
+ GNUNET_SERVER_client_keep (client);
}
* @return number of bytes written to buf
*/
static size_t
-transmit_message (void *cls,
- size_t size,
- void *buf)
+transmit_message (void *cls, size_t size, void *buf)
{
struct ClientList *cl = cls;
char *cbuf = buf;
size_t ret;
cl->th = NULL;
- if (buf == NULL)
- {
- /* 'cl' should be freed via disconnect notification shortly */
- return 0;
- }
+ if (NULL == buf)
+ {
+ /* 'cl' should be freed via disconnect notification shortly */
+ LOG (GNUNET_ERROR_TYPE_DEBUG,
+ "Failed to transmit message from NC queue to client\n");
+ return 0;
+ }
ret = 0;
- while (cl->pending_head != NULL)
- {
- pml = cl->pending_head;
- cl->pending_head = pml->next;
- if (pml->next == NULL)
- cl->pending_tail = NULL;
- msize = ntohs (pml->msg->size);
- if (size < msize)
- break;
- memcpy (&cbuf[ret], pml->msg, msize);
- ret += msize;
- size -= msize;
- GNUNET_free (pml);
- }
- if (cl->pending_head != NULL)
- cl->th = GNUNET_SERVER_notify_transmit_ready (cl->client,
- ntohs (cl->pending_head->msg->size),
- GNUNET_TIME_UNIT_FOREVER_REL,
- &transmit_message,
- cl);
+ while (NULL != (pml = cl->pending_head))
+ {
+ msize = ntohs (pml->msg->size);
+ if (size < msize)
+ break;
+ GNUNET_CONTAINER_DLL_remove (cl->pending_head, cl->pending_tail, pml);
+ LOG (GNUNET_ERROR_TYPE_DEBUG,
+ "Copying message of type %u and size %u from pending queue to transmission buffer\n",
+ ntohs (pml->msg->type), msize);
+ memcpy (&cbuf[ret], pml->msg, msize);
+ ret += msize;
+ size -= msize;
+ GNUNET_free (pml);
+ cl->num_pending--;
+ }
+ if (NULL != pml)
+ {
+ LOG (GNUNET_ERROR_TYPE_DEBUG,
+ "Have %u messages left in NC queue, will try transmission again\n",
+ cl->num_pending);
+ cl->th =
+ GNUNET_SERVER_notify_transmit_ready (cl->client, ntohs (pml->msg->size),
+ GNUNET_TIME_UNIT_FOREVER_REL,
+ &transmit_message, cl);
+ }
+ else
+ {
+ GNUNET_assert (0 == cl->num_pending);
+ }
return ret;
}
*/
static void
do_unicast (struct GNUNET_SERVER_NotificationContext *nc,
- struct ClientList *client,
- const struct GNUNET_MessageHeader *msg,
- int can_drop)
+ struct ClientList *client, const struct GNUNET_MessageHeader *msg,
+ int can_drop)
{
struct PendingMessageList *pml;
uint16_t size;
- if ( (client->num_pending > nc->queue_length) &&
- (GNUNET_YES == can_drop) )
- return; /* drop! */
+ if ((client->num_pending > nc->queue_length) && (GNUNET_YES == can_drop))
+ {
+ LOG (GNUNET_ERROR_TYPE_INFO,
+ "Dropping message of type %u and size %u due to full queue (%u entries)\n",
+ ntohs (msg->type), ntohs (msg->size), (unsigned int) nc->queue_length);
+ return; /* drop! */
+ }
if (client->num_pending > nc->queue_length)
- {
- /* FIXME: consider checking for other messages in the
- queue that are 'droppable' */
- }
+ {
+ /* FIXME: consider checking for other messages in the
+ * queue that are 'droppable' */
+ }
+ client->num_pending++;
size = ntohs (msg->size);
pml = GNUNET_malloc (sizeof (struct PendingMessageList) + size);
- pml->msg = (const struct GNUNET_MessageHeader*) &pml[1];
+ pml->msg = (const struct GNUNET_MessageHeader *) &pml[1];
pml->can_drop = can_drop;
+ LOG (GNUNET_ERROR_TYPE_DEBUG,
+ "Adding message of type %u and size %u to pending queue (which has %u entries)\n",
+ ntohs (msg->type), ntohs (msg->size), (unsigned int) nc->queue_length);
memcpy (&pml[1], msg, size);
/* append */
- if (client->pending_tail != NULL)
- client->pending_tail->next = pml;
- else
- client->pending_head = pml;
- client->pending_tail = pml;
+ GNUNET_CONTAINER_DLL_insert_tail (client->pending_head, client->pending_tail,
+ pml);
if (client->th == NULL)
- client->th = GNUNET_SERVER_notify_transmit_ready (client->client,
- ntohs (client->pending_head->msg->size),
- GNUNET_TIME_UNIT_FOREVER_REL,
- &transmit_message,
- client);
-}
+ client->th =
+ GNUNET_SERVER_notify_transmit_ready (client->client,
+ ntohs (client->pending_head->
+ msg->size),
+ GNUNET_TIME_UNIT_FOREVER_REL,
+ &transmit_message, client);
+}
/**
* @param can_drop can this message be dropped due to queue length limitations
*/
void
-GNUNET_SERVER_notification_context_unicast (struct GNUNET_SERVER_NotificationContext *nc,
- struct GNUNET_SERVER_Client *client,
- const struct GNUNET_MessageHeader *msg,
- int can_drop)
+GNUNET_SERVER_notification_context_unicast (struct
+ GNUNET_SERVER_NotificationContext
+ *nc,
+ struct GNUNET_SERVER_Client *client,
+ const struct GNUNET_MessageHeader
+ *msg, int can_drop)
{
struct ClientList *pos;
-
- pos = nc->clients;
- while (NULL != pos)
- {
- if (pos->client == client)
- break;
- pos = pos->next;
- }
- GNUNET_assert (pos != NULL);
- do_unicast (nc, pos, msg, can_drop);
+
+ for (pos = nc->clients_head; NULL != pos; pos = pos->next)
+ if (pos->client == client)
+ break;
+ GNUNET_assert (NULL != pos);
+ do_unicast (nc, pos, msg, can_drop);
}
* @param can_drop can this message be dropped due to queue length limitations
*/
void
-GNUNET_SERVER_notification_context_broadcast (struct GNUNET_SERVER_NotificationContext *nc,
- const struct GNUNET_MessageHeader *msg,
- int can_drop)
+GNUNET_SERVER_notification_context_broadcast (struct
+ GNUNET_SERVER_NotificationContext
+ *nc,
+ const struct GNUNET_MessageHeader
+ *msg, int can_drop)
{
struct ClientList *pos;
-
- pos = nc->clients;
- while (NULL != pos)
- {
- do_unicast (nc, pos, msg, can_drop);
- pos = pos->next;
- }
+
+ for (pos = nc->clients_head; NULL != pos; pos = pos->next)
+ do_unicast (nc, pos, msg, can_drop);
}